The United States' killing of Gen. Qassem Soleimani will not deter Iranian resistance, a senior commander said Friday as tensions mount in the buildup to the first anniversary of the drone strike.

The U.S. killed Soleimani, leader of the Revolutionary Guards' Quds Force, in Iraq on Jan. 3, 2020. Washington had accused him of masterminding attacks by Iranian-aligned militias on U.S. forces in the region.

Days after the U.S. drone strike, Iran retaliated with a rocket attack on an Iraqi air base where U.S. forces were stationed, and Iranian forces on high alert mistakenly shot down a Ukrainian passenger airliner taking off from Tehran.

Esmail Ghaani, who succeeded Soleimani as head the elite Quds Force, said on Friday Iran was still ready to respond.

"From inside your own house, there may emerge someone who will retaliate for your crime," he said at a televised event to mark the anniversary at Tehran University.

"American mischief will not deter the Quds Force from carrying on its resistance path," he added.

Two U.S. B-52 bombers flew over the Middle East on Wednesday in what U.S. officials said was a message of deterrence to Iran ahead of the first anniversary.

On Thursday, Iran’s Foreign Minister Mohammad Javad Zarif accused U.S. President Donald Trump of attempting to fabricate a pretext to attack Iran and said Tehran would defend itself forcefully.

Representatives of Iran’s regional allies and movements in Lebanon, Iraq, Syria, Yemen and Gaza also spoke at Friday's anniversary event.